In German patent application No. P 34 28 922.4, such a disconnectable connector and its disadvantages have already been described and the invention for the elimination of the disadvantages of this very type has been shown in detail. The connectors of the above mentioned application are of the kind which, according to currently valid norms, are intended only for vehicles with a voltage of 6 to 12 volt. Those are commonly to be found on passenger cars and smaller trucks.
Bigger trucks, especially those intended for trailer traffic are, however, operated with a voltage of 24 volts (DIN ISO 1135). Although those are equipped with a seven pin connector, too, they differ from the 6 and 12 volt types as regards their structure.
The present invention relates to disconnectable connectors for 24 volt systems.
Compared to a 6 to 12 volt (DIN ISO 1724) socket with a rigid contact insertion with pins and tubes, the 24 volt type has seven free-standing contact pins, wherein one is thicker in diameter compared to the others in order to provide a coding. Accordingly, the plug of the 24 volt type has a rigid front closing plate in which seven contact tubes are inserted homologously to the socket, whereas in the connector of the 6 to 12 volt version, the respective contacts are free-standing homologously in the form of pins and tubes.
Another peculiarity of the 24 volt version consists in the fact that there is one socket on the motor vehicle as well as one on the trailer which, if required, is being connected by means of a cable with a plug at each of its ends.
Of course, the necessity of additional contacts between towing vehicles and trailers exists for applications with 24 volt systems as well. At present this problem is solved by installing a special second connector which is different from the normal one in technical and constructive features to avoid confusion. These connectors are known under the names "24 N" (DIN ISO 1185) for the regular connector and "24 S" (DIN ISO 3731) for the additional one.
The disadvantage of using this additional model lies as well in the uneconomic installation, difficult use, as well as in increased costs by using two separate and different sockets. Moreover, two separate connection cables each with two different connectors are necessary.
The present invention provides a modification to the plug and socket of 24 volt systems wherein they show more connectors additional to the existing seven but which are, however, perfectly compatible with the existing connectors. Moreover, it is to be more favorable in terms of production and use than the conventional separate connectors.